1. Field of the Invention
The invention relates to a novel process for preparing free radical polymerizable monomeric unsaturated organosilicon esters by accelerating the reaction, thereby greatly reducing the reaction time, without polymerizing the free radical polymerizable monocarboxylic acid or the free radical polymerizable monomeric unsaturated esters. The process comprises reacting a cyclosilalkoxane having the general formula: ##STR2## wherein R is a monovalent hydrocarbon radical free of aliphatic unsaturation, R' is selected from the group consisting of H and CH.sub.3 and n is an integral of from about 1 to 2 inclusive with a free radical polymerizable monocarboxylic acid. The process steps comprise contacting at least stoichiometric amounts of the cyclosilalkoxane with at least stoichiometric amounts of the free radical polymerizable monocarboxylic acid in the presence of from at least about 25.0 percent by weight, based on the total weight of the solution, of a solvent which will form an azeotrope with water, from about 0.1. percent to about 3.0 percent by weight, based on the total weight of the solution, of a protonating catalytic acid and from about 0.01 percent to about 1.0 percent by weight, based upon the total weight of the solution, of an inhibitor which assists in preventing free radical polymerization of either the final product i.e. the monomeric ester, or the monocarboxylic acid. The process further comprises heating the solution to a temperature of from about 70.degree. C. to about 135.degree. C. while preferably blanketing the reaction with air. The process further comprises continuously removing water, which is produced by the reaction, from the solution during the reaction. This process produces a substantially pure monomeric unsaturated organosilicon ester, in an accelerated manner, without polymerizing the polymerizable monocarboxylic acid or polymerizing the polymerizable organosilicon ester.